Along with emergence of numerous new advanced multimedia applications, for example, deployment of 3D television, remote medical services, online gaming, interactive video electronic learning and other services, there has been a significantly growing demand for a network bandwidth carrying these applications. The Next Generation Passive Optical network (NG-PON2) has become a hot topic of the Telecommunication Standardization Sector of the International Telecommunications Union (ITU-T) and the Full Service Access Network (FSAN). The majority of operators expect the NG-PON2 to offer a larger bandwidth, a high splitting ratio, a longer transmission distance and a higher access capacity. At present the demands of the NG-PON2 have been ascertained by the FSAN and the ITU-T to increase an available bandwidth to a rate up to 40 Gb/s.
In the recent FSAN meeting, among all the candidate technical solutions, the Time Wavelength Division Multiplexing-Passive Optical Network (TWDM-PON) has been considered in the industry as a primary solution to the NG-PON2, where 4 10G XG-PONs are stacked into the TWDM-PON with a typical splitting ratio of 1:64 to thereby achieve an aggregate rate of 40 Gb/s in the downlink and 10 Gb/s in the uplink. Within a single wavelength, the TWDM-PON reuses downlink multiplexing and uplink access techniques, a timeslot granularity, a multicast capability and a bandwidth allocation mechanism of XG-PON (that is, 10GPON).
There are typically the following common demands in existing applications of the TWDM-PON:
1. If there are only a few active optical network units, then all the optical network units need to be adjusted to operate at the same uplink wavelength and downlink wavelength in order to save energy.
2. If an infrastructure provider of the TWDM-PON leases the infrastructure network to a number of virtual network operators, then optical network units corresponding to the respective different virtual network operators need to be provided with corresponding wavelengths. This requires the TWDM-PON to be capable of configuring effectively the relevant optical network units to enable them to operate at uplink wavelengths and downlink wavelengths leased to the virtual network operators.
3. With respect to the second demand, a customer may also be switched between the respective different virtual network operators, and this further requires the TWDM-PON to be capable of adjusting the uplink wavelengths and the downlink wavelengths of the optical network units in a timely manner.
4. If there are too may optical network units operating at the same uplink wavelength and the same downlink wavelength, then the TWDM-PON needs to adjust uplink wavelengths and downlink wavelengths of some optical network units to reduce a corresponding load for the purpose of load balancing.
However due to a large number of optical network units in an access network, it may be rather complex or difficult to configure statically the wavelengths of the optical network units or adjust manually the wavelengths of the optical network units in order to satisfy the foregoing four demands.
In view of this, there is a need of a solution to remote automatic configuration of an uplink wavelength and a downlink wavelength of an optical network unit in a TWDM-PON system (particularly during an optical network unit activation progress) to thereby satisfy effectively the foregoing exemplary demands.